May 6, 2011 -- More than half of people with attention deficit hyperactivity disorder (ADHD) also have trouble regulating their emotions, and that difficulty may be passed through families, a new study shows.

"Any sort of reflexive, emotionally laden reaction that would not be politic or thoughtful or helpful," says study researcher Craig B. H. Surman, MD. Surman is an instructor in psychiatry in the Massachusetts General Hospital Pediatric Psychopharmacology and Adult ADHD Program.

"It's not just people with mental health challenges that have issues regulating their emotions. Everyone does to some extent, but hopefully, in most cases it's when people are really maxed out or strained or stressed," Surman says.

"Folks who have deficient emotional self-regulation, we feel, don't have inhibitory capacity to censor emotional reactions even when they're not under these kinds of stresses."

What's more, it appears that this inappropriate emotional reactivity appears to be shared among siblings, though researchers aren't sure if genetics or a family environment is the reason.

"Is it a neurobiological thing in these families, or a learned thing?" Surman asks.

Emotional Outbursts and ADHD

For the study, researchers recruited 83 people: 23 with ADHD alone, 27 with ADHD plus DESR, and 33 people with neither condition for comparison. Researchers then enrolled 128 siblings of each of the participants.

Clinicians who were kept in the dark about which group participants belonged to evaluated each person in the study to independently confirm their diagnosis and to measure any DESR symptoms.

People with ADHD were considered to have DESR if they also reported emotional-control symptoms that were worse than those reported by 95% of a large comparison group of people without ADHD.

More than half of those with ADHD enrolled in the study (55%) were also emotionally reactive.

As expected, ADHD was more common in siblings of the original participants with ADHD than in siblings of the comparison group. Previous studies have suggested that ADHD may run in families.

The surprising thing to researchers was that ADHD and DESR appeared to only co-occur in siblings of original participants with both sets of challenges.

"I think that what we've demonstrated is that there's a subset of people who have attention deficit hyperactivity disorder who can't control their emotional reactions, also," Surman says.

Because mental health conditions like ADHD, depression, and generalized anxiety disorder often occur together, the researchers also asked participants about symptoms and signs that might indicate that another mental illness could account for the emotional volatility they were feeling.

"We found you can individually remove any of the major mental health conditions that we inventoried and people still are reporting these kinds of irritable, emotional overreactions," Surman says.

The study is published in the American Journal of Psychiatry.

Attention, Emotions, and the Brain

Though researchers are still trying to understand the role of different brain structures in ADHD, one fold of tissue in the middle of the brain, called the cingulate gyrus, appears to be playing a big role.

"It's so tied to key regulatory systems for behavior and attention and also emotion that it's highly implicated as a likely place of some sort of issue for ADHD," Surman says.

Scans that look at the activity of the brain as it is working, called functional magnetic resonance imaging (fMRI) scans, have also shown that the activity of the cingulate gyrus in the brains of ADHD patients appears to be lower compared to people without ADHD.

When those same patients are given stimulant medications, the activity of the cingulate gyrus appears to normalize.

In addition to medications, cognitive behavioral approaches to therapy may help.

A paper published last year in The Journal of the American Medical Association, which Surman co-authored, found that two-thirds of patients with ADHD who got 12 weekly counseling sessions of cognitive behavioral therapy report at least a 30% reduction of their symptoms, compared to one-third of a comparison group that was taught relaxation techniques.